The study of pediatric sarcomas including Ewing's sarcoma, rhabdomyosarcoma, and undifferentiated sarcomas, as well as other sarcomas, is being undertaken in two areas: biological studies and therapeutic trials. The biological studies address: 1) in vitro tissue culture evaluation and characterization of the cell lines from tumors of patients with these sarcomas; 2) in vitro differentiation of cell lines derived from tumors of patients with these sarcomas; 3) development of monoclonal antibodies to pediatric sarcomas; 4) definition of the cytogenetics of pediatric sarcomas; and 5) in vitro radiation and chemosensitivity of cell lines derived from tumors of patients with these sarcomas. The cytogenetic characterization of Ewing's sarcoma, peripheral neuroepithelioma has confirmed the translocation Tau (11;22) in all cell lines studied with these disorders. The therapeutic studies address: 1) improvement in therapy for patients with high risk pediatric sarcomas a) by improving the initial induction rate using an intensive induction and b) by utilizing intensive consolidation including high dose chemotherapy, total body radiotherapy, and autologous bone marrow reinfusion; 2) improvement in therapy for patients with moderate risk pediatric sarcomas; 3) improvement in the detection, evaluation, and treatment of pulmonary metastasis in patients with pediatric sarcomas; 4) careful evaluation of the short and long term effects of chemotherapy and total body radiotherapy on cardiac and pulmonary function, as well as other major organ systems; 5) evaluation of the efficacy and toxicity of autologous bone marrow transplantation in the treatment of pediatric sarcomas using a new chemotherapeutic and radiotherapeutic regimen. Since the 83-C-73 protocol was begun in early 1983 over 45 patients have been entered. For newly diagnosed patients the initial complete remission rate has been greater than 85% and greater than 70% remain in remission. These figures represent improvement over previous regimens utilized at this institution.